This invention relates to the depositing of films of metal, for example, by laser chemical vapor deposition. The invention also relates to an improved metal-film electrode which is both highly conductive and highly transparent to light in the ultraviolet, visible, and near infrared spectra. The invention is more specifically directed to a highly transparent electrically conductive metal film that can be used for spectroscopy and for electrochemical, catalytic, charge-transfer, and photochemical processes at electrode surfaces.
Light-transmitting platinum films have been prepared, for example, by photoelectrodeposition onto indium phosphide semiconductor phosphates from dilute aqueous perchloric acid solutions of platinum oxide. Because a wet process is used in making these films, they have low physical strength. Also, because photoelectrodeposition is used, the process is clearly limited to conducting substrates. Semi-transparent platinum films have been produced, limited to a thickness of about 10 nm, by the use of RF/DC sputtering. Previous processes employing laser chemical vapor deposition have produced platinum films but these have not been both conductive and transparent.